Many industries use a repetitive manufacturing process to produce their products. The process may include a production or assembly sequence, which is a scheduling of orders in which a series of orders in the sequence are processed in each assembly station for a certain amount of time. Each order may represent a fixed rate in the sequence, such as one minute. Thus, for example, each minute an item will move from one assembly station to the next in an assembly line.
In case of highly configured products and/or product families, however, some orders require more time than orders at particular assembly stations. For example, a three-cylinder engine may take more time than a six-cylinder engine due to more components. Conventionally, assembly lines may operate on time slots with constant durations. Given this information, conventional sequencers may calculate a sequence order to produce a certain number of products (e.g., three, four, and six cylinder engines) based on capacity (e.g., 1000 engines) for a particular day. For example, assume A=three cylinder engines, B=four cylinder engines, and C=six cylinder engines. The production sequence in order to produce 1000 engines in the day may be A, A, B, A, C, B, and so forth.
There is a desire to optimize capacity and sequence. One conventional method provides calculation of a capacity and a sequence based on the capacity by a single order with a lot size equal to one. When there is a change to the capacity or if one or more orders in the sequence needs to be deallocated or shifted in the sequence (e.g., due to a production disturbance, backlog, quality issues, material shortages), the entire production sequence (or what remains of the sequence to be performed) needs to be resequenced and new sequencing information is generated. For example, if the production sequence has 1000 slots and a backlog occurs which requires the production sequence to be rearranged in order to maintain capacity requirements and continue with production, conventional systems may require a capacity and resequencing process to be performed whereby the resequencing process generates new sequencing information (e.g., for all 1000 orders in the slots). Each resequencing process takes time and consumes processing resources.